The invention relates to a tape movement control system for loading magnetic recording tape into tape cassettes at a high rate of speed, and more particularly relates to an electronic control circuitry for regulating the speed of the tape in order to permit vacuum column tension regulation of the tape during movement.
In a tape cassette loader, a predetermined length of tape is paid out from a spool and loaded within a tape cassette. Such cassette loaders include a single source of tension regulating the tension between the supply spool and the spool of the tape cassette. See for example, U.S. Pat. No. 3,753,834 issued to James L. King on Aug. 21, 1973.
In the art of tape cassette loading, the speed at which a cassette may be loaded with tape determines the quantity of cassettes produceable per machine in a given work day. To produce more cassettes, more machines would be necessary resulting in higher costs for machines, labor in operating the machines, maintenance and energy needs. It would be highly desirable to increase the speed at which the present state of the art machine can load tape into a single cassette.
However, as the cassette spool within the cassette is driven at extremely high rates of speed in order to wind tape extremely fast into the cassette, the tape bearing surfaces inside the cassette begin to heat up from frictional drag of the tape and of the spool of tape building up within the cassette, and the cassette begins to melt. In order to overcome this problem the tension on the tape is regulated by using a pair of vacuum tension regulators in which a very low tension level is applied to the tape portion being taken up into the cassette and a higher level of tension is applied to the tape portion being paid out from the supply spool. See U.S. Pat. Application, Ser. No. 199,924, filed on even date herewith, in the names of David O. Neathery and David W. Kincheloe which describes the dual vacuum column regulation in detail.
However, when driving such a dual vacuum column system at extremely high rates of speed, the tape loop within the vacuum column must be controlled at its high rate of movement. The instantaneous speed of the tape leaving the vacuum column may be so fast that the control of tape moving into the column may not respond quickly enough to prevent the tape loop from wholly leaving the vacuum column unless, of course, the vacuum column is unrealistically long.
Therefore, it is an object of the present invention to anticipate the need for tape within the vacuum column of the tension regulator and to feed tape into the column according to anticipated need during high speed movement of tape. This permits the length of the vacuum column to be smaller than would be neded if anticipated need were not provided.